Jack receptacle-testing device



G. W. ATKINSON JACK RECEPTACLE TESTING DEVICE @ML 26 9 l92 i Filed March l0. 1925 INI/ENTOR. ZZZFQ si@ 7% ATTORNEY.

Patented Oct.. 26, 1926.

STATES P A T E F F uienv REcEriraonE-rns'rine nnvren.

Application led March 10, 1925. Serial No. 14,421. I

. This invention relates to improvements in a type of jack receptacle testing device. It is of particular utility where permanentI means is to be provided in an electrical circuit for making aquick, easy, and .safe method of ascertaining the `load condition on a current consuming apparatus.v The Said device is formed With/a threaded neck portion so thatthis part willt into a hole,

`as for instance, theL knockout hole, in the wall of a sheet iron cabinet, box, or casing which encloses some 'part of an electrical circuit. It permitsthat no entra'space. need be provided for its installation 1n existing or lstandard arrangements of an \ele ctr1cal system. V0n the threaded neck portion of the device or receptacle which protrudes through aI wall of saidcabinet, box,- or casing a lock nut is provided-to permanently hold the receptacle in place. In case it is desirable to .install the receptacle entirely within al cabinet or other enclosure, I have provided a special iormof bracket as will be described and which is formed with an opening to 'receive the threaded neck of the receptacle. The opening in this bracket re- .ceives the threaded neck portion of the receptacle after which the lock nut may threaded onto the neckvportion to hold it as above stated. ln order to secure the receptacle vpermanently in the wall or side oir a cabinet or enclosure, the bracket is then bolted 'to the side of same as indicated.v

rlhe electrical connection to this receptacle is made by connecting any series wire to the usual two lugs, as shown. ln its application the improvement is not intended to be limited to any particular arrangement of being connected in the circuit, but is generally connected between the load and some i protective device such as fuses or circuit breakers lllhisterm of receptacle is compact and readily lends itself in that it may be readily vinstalled in an existing installation of elec.- trical circuits, which may be partly encled in a cabinet, box or other casing.

Generally s eaking it occupies a comparatively smal volume of space and is well 'adapted for installation in the sides or corners of cabinets, boxes, or enclosures where itwill not occupy s aces that are use,`

ful 'tor other purposes, an at the same time' `it will possess therequired spacing distances B5. for electrical insulations.v

The improvement broadly considered comprises a main body which is composed of iiisulatingmaterial. It isformed with a small rectangular aperture in the top end of the said neck portion of the receptacle which forms a space for the insertion of the test plug. An insulating cover is provided over this aperture and arranged to be readily moved from the closed to the open position or vice versa. The current carrying members of the receptacle are composed of a metal liavingfa spring action as Well as being a good electrical conductor. In order to insure an adequate'electrica'l contactbetween the adjacent leaves of the current carrying members of the receptacle, I have installed the steel springs. These springs together with the current carrying members are shaped and installed in such a manner that they will permit the insertion of the testing plug and still retain the necessary pressure between electrical contacts at all positions of the test plug. The current carrying members on the receptacle are laminated in order to `insure better electrical contacts and to permit ofgreater ease in `operation when making tests. y

A portable testing plug is provided, as indicated, having a mainfbody which is constructed of insulating material. llt is divid ed longitudinally in practically two equal sections which are held together `with bolts. Theset of bolts on each end serve the additional function of securing the handle supports to the'main body. By having the main body divided into two sections, the electrical connections to lugs and test plugs are made readily accessible. rllhe two'rnain halves ot contactors of the test plug are separated electrically by means of the thin layer of insulating material. 0n the lugs attached to each test plug contactor, there are attached two leadsvor electrical conductors which may be of suitable vlength to accommodate connection to an ammeter or wattvmeter/used in nia-king tests. 'lo understand 'now quite exactly' how a device embodying my invention functions andy operates in actual service after it has been arranged and connected practically as shown in the figures, or in some other way within the -purview of the invention reference may now be had to the drawings. Here it will be seen that the current carrying part ot the receptacle is connected'in series with the circuit and isaccessibleior insertion of the test plugcontactors.` When thejcontactors of the plug ,the handle part and the contactor blades.

are rst started between the current carrying parts of the receptacle, a portion of the electrical current going through the receptacle conductors is diverted to the circuit being made through the test plug with its connected measuring instrument. The amount of current going through this instrument gradually increases as the plug contactor is further inserted, but it reaches a maximum amount when the two main sections of receptacle current carrying parts are electrically separated by the test plug contactors pushing them apart. After the proper readings of the load conditions are obtained the test plug is pulled out of the receptacle and the current flowing through the test instru.- ment is gradually decreased in amount as the plug is removed. The construction of this device is such that it is impossible within all practical means of operation, to cause an open circuit, short circuit, or ground, while making a test connection, or disconnecting the same. The current is gradually built up and decreased through the testing instrument during the cycle of testing.

There is no arcing at any place in the circuit as the current is gradually transferred.

to and from the circuit of the testing instrument. This condition obtains within all practical time taken for inserting or removing the test plug.

l have thus far referred to arrangements similar to the structure shown, which may he installed in existing cabinets, boxes or other enclosed devices Jfor electrical circuits, but I do not intend to imply that my invention is not equally available for installation in cabinets, or boxes especially made for enclosing same and connected in the electrical circuit system.. However, due vto-its compactness and simplicity of installation it 1s particularly well adapted for being insta led in existing cabinets, boxes, or other enclosing devices now in place, or in such standard cabinets, boxes orother enclosing devices which may be installed at a future time.

Referring to the drawings:

Fig. 1 is a plan view ofthe receptacle, showing in dotted lines the terminals and the opening which receives the blades of the contactor.

Fig. 2 is a top plan view ot the contacto assembly.

Fig. 3 isa vertical sectional view on the line 3-3 of Fig. 1 showing the lexible contact leaves, the threaded neck portion, and the lugs.

Fig. 4 is a side view of Fig. 2 showing Fig. 5'is a detail view of the device installed entirely within one corner of a cabinet or casing.

Fig. 6 is an enlarged side view partially in section on the line 6-6 of Fig. 5 show- 1 designates, asa whole, the body part' of the receptacle which is formed with a hollow recessed interior part 2. Located within this recessed part are the U-shaped contact spring leaves 3 and 4; one end of l which is attached to the opposite interior walls of the recessed part by means ot the bolts and nuts 5 and 6; the other or inner ends of these leaves extend downward in contacting relation to each other toward the lower end of the recessed part 2, as shown. Disposed between the outermost leaves 3.4and 4 and the inner wall of the recessed part are filler or spacing plates 7. Each set of contact leaves comprises a plurality of membersl as shown, and are of varying lengths. 8 and 9 designate two curved springs which are interposed between the lower ends ot the innermost ones of the leaves 3 and 4 and the inner ends of the bolts 5, to which bolts theyare secured by the nuts 6. These curved springs are for the purpose of normally retaining the depending inner ends of the Contact springs The lower outer ends 14 and 15 ot thel leaves 3 and 4 are bent at right angles, as shown, and extend outwardin opposite directions below the lower ends of the member 1. These ends al'ord attaching means for the usual cable connections 16 and 17, as with the bolt 18..

The receptacle 1 is installed or att-ached to a wall of metallic casing as 19 by inserting the threaded neck portion 10 in a knockout opening. lt is secured in place by means of the nut 20, see Figs. 7 and 8.

AS a modification of installing the receptacle 1 in a casing or housing l make use of the bracket 21 having the arm part y22 which is formed with an opening 23, see Fig. 6, to receive the threaded neck part 10 of the receptacle 1.l The lock nut 20`is threaded onto this neck part which retains the recept-,tele in place on the bracket. Y The 'purpose aanwas bracket is secured to the wall of the casing by means of the bolts 24 which pass through the openings25. ln Fig. 5 the receptacle is normally enclosed in the metallic casing; the door of which is usually closed and locked.

In Fig. 7 thc receptacle 1 is enclosed in the casing 19 but its outer threaded end 10 projects through a knockout opening in a wall of the same and is secured in place by the lock nut 2O as before described.4 This iigure and Fig. 5 show the wires 16 and 17 connected to the terminals 14 and 15 ol the receptacle. Fig. 7 shows a switch operating handle 26. 27 are the fuses which are removably inserted in the knife blades 28.

Referring now to the contactor construction shown in Figs. 2 and 4, 29 and 30 are the threeoppositely located blades of unequal length, as shown. The innermost blades are separated by the strip of insulation 31. The blades 29 and 30 extend upward and are bent in opposite directions to form the branches 32 and 33. 34 and 35 are two clamping members between which the branches are clamped by means of the bolts 36 and 37. The bolts 37'r1 serving the of electrically connecting the branches to the lugs 38 and 39. The bolts 36 serve also to attach the handle supporting bars 39 to the upper ends of which the handle 40 is attached. 41 is an electrical measuring instrument as a wattmeter, or ammeter which is lconnected by the wires 42 to the lugs 38 and 39.

It will be observed that whenvthe contactor blades 29 and 30 are inserted between the outermost leaves 3 and 4 that Athe current which normally Hows through the leaves 3 and 4 is divided, part iowing through the leaves and part through the contactor blades 29 `and 30 as these blades are inserted. The circuit is not, therefore, opened at any time when the blades 29 and 30 are removed. rlflie reverse operation takes place when the contactor blades are Withdrawn. In other words the load may be measured at any time without breaking the circuit, when the contactor blades are inserted the springs 8 and 9 yield to permit the insertion, and, when the blades are removed they will automatically return the leaves 3 and 4 together again as the blades are withdrawn. The current always flows in series through the leaves 3 and 4 and, in series through the contacter blades 29 and 30 when inserted.

lVhat I claim is:

An electrical testing device comprising an insulating member formed with a recessed portion, the insulating member having` a threaded extension portion `for securing the member to a iXed support, which is -formed with an opening to receive` the thread extension, a nut engaging the threaded extension of the insulating member for securing the said member to the support,`

electrical contact members located within the recessed portion, means for forcing said members together in contact with each other, the insulating member' having an opening through the threaded extension and designed for inserting la. single contacter. member be# tween the normally closed electrical contact members, the construction and arrangement being such that the contacter may be inserted and removed without breaking the circuit.

GEURGE W. ATKINSN. 

